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51.
Interaction of mycoplasmas and phagocytes 总被引:2,自引:0,他引:2
Aspects of the interaction of certain mycoplasmas with macrophages and neutrophils in vivo and in vitro have been studied using two systems, one involving M. pulmonis in mice and the other involving M. bovis with bovine leucocytes. Studies with M. pulmonis indicated that the disappearance of viable organisms from the peritoneal cavity was not enhanced in SPF mice in which a peritoneal exudate rich in neutrophils had been induced. However, viable M. pulmonis organisms disappeared more rapidly from the peritoneal cavities with exudates containing increased numbers of macrophages. Experiments in vitro studied the opsonic effect of bovine IgG isotypes for bovine neutrophils and alveolar macrophages. Both IgG1 and IgG2 promoted killing of M. bovis by alveolar macrophages but IgG2 was more effective than IgG1 at promoting mycoplasma killing by neutrophils. Further studies in vitro indicated that certain bovine mycoplasma could inhibit killing of Escherichia coli by bovine neutrophils. 相似文献
52.
The effect of the Abortion Act on gynaecological work in one provincial teaching hospital is that despite an increase in patient turnover of 45% the waiting list has increased by 200%. It is suggested that the Act has had little effect on the birth rate or illegitimacy and that there may have been an increase in criminal abortion. 相似文献
53.
Growth of Chikungunya Virus in Baby Hamster Kidney Cell (BHK-21-Clone 13) Suspension Cultures 总被引:2,自引:2,他引:0 下载免费PDF全文
This report describes the methods used to obtain high titers of chikungunya virus with suspension cultures of BHK-21-clone 13 cells. The cells were grown at 37 C to a cell concentration of 10(6) to 2 x 10(6) per ml. After maximum cell growth, the cells were inoculated with chikungunya virus at a multiplicity of 1 to 2 50% suckling mouse intracerebral lethal doses (SMICLD(50)) per cell in the spent Eagle's minimum essential medium for suspension cultures (MEMS), or the cell cultures were centrifuged at 200 x g and resuspended in either fresh MEMS or medium 199 prior to inoculation. The medium used had no effect on virus titer. The inoculated cultures were incubated at 34 C until the cell viability dropped to 30%, which usually occurred 28 to 30 hr postinoculation. After these procedures, chikungunya virus titers of log(10) 10.3 to 11.8 SMICLD(50) per ml were obtained. 相似文献
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Howard L. Clark J.F.M. Ronald L. Stuckey J.W.T. R.E.S. B. Lowy Thomas C. Rambo 《Economic botany》1974,28(2):237-244
56.
A mass-spectrometric sequence study of the enzyme ribitol dehydrogenase from Klebsiella aerogenes 总被引:10,自引:6,他引:4
Howard R. Morris Dudley H. Williams Graeme G. Midwinter Brian S. Hartley 《The Biochemical journal》1974,141(3):701-713
The first detailed results of the application of a low-resolution mixture analysis approach to the sequence analysis of an enzyme, ribitol dehydrogenase, are given. Examples of the interpretation of the spectra of peptide mixtures derived from this protein are described. Evidence for new fragmentation patterns observed is reported, together with an explanation of the generation of ambiguous sequences by use of a low-specificity enzyme, thermolysin. The overall sequencing strategy evolved is assessed. 相似文献
57.
Howard R. Morris Karen E. Batley Nigel G. L. Harding Richard A. Bjur John G. Dann Rodney W. King 《The Biochemical journal》1974,137(2):409-411
An elastase digest of a protein of unknown structure, dihydrofolate reductase, was studied by mass spectrometry. This soluble digest contained a large number of small peptides in different yields, within the ideal molecular-weight range (200-1200) for mixture-analysis mass spectrometry. Sequences of the major component peptides in the digest are reported. 相似文献
58.
Fluorescence microscopy of Douglas fir foliage epiflora 总被引:2,自引:0,他引:2
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A cytological and cytochemical examination of Saprolegnia terrestris Cookson was undertaken to resolve the conflict of opinion regarding the life cycle of fungi in the Saprolegniaceae, i.e., whether meiosis is zygotic or gametic. Microspectrophotometric analysis reveals that pre-divisional oogonial and antheridial nuclei are 4C; a subsequent reduction division in the sex organs produces 1C male and female gametes. These division products coexist in the developing oospore and presumably fuse to produce the diploid zygote. Analysis of the somatic hyphal nuclei shows a 2C DNA content, with the characteristic skew and bimodal character indicative of predominantly G1, and some S-period and G2 types. The evidence is completely consistent with gametic meiosis, i.e., a predominant diploid vegetative phase and short haploid phase, and refutes the notion of zygotic meiosis. Further ramifications of the work are discussed along with preliminary results of related work in progress. 相似文献